class Program
{
  static var are = new AutoResetEvent (false);
 
  static void Main()
  {
    var t1 = new Thread (Task);
    t1.Start();
    Thread.Sleep (3000);                  
    are.Set();  //send a signal
    Console.WriteLine ("Main thread completed");
    Console.Read();
  }
 
  static void Task()
  {
    Console.WriteLine ("Waiting...");
    are.WaitOne(); // Wait a signal
    Console.WriteLine ("Signal recived");
  }
}